Despite their popularity, copper bracelets and magnet wrist straps do not reduce the symptoms or progression of rheumatoid arthritis, according to a new study from the University of York.

The study, published in the journal PLoS One, is the first randomized controlled trial to examine whether copper bracelets and magnetic wrist straps had any effect on patients with rheumatoid arthritis. Researchers followed 70 patients with active symptoms for five months. They each wore four different devices for five weeks at at time, providing blood samples so doctors could see if there were any changes in inflammation.

Dr. Stewart Richmond, a research fellow in the Department of Health Sciences at York, and lead author of the study, said people who suspect they have rheumatoid arthritis should consult a doctor for early treatment rather than trying these types of devices because uncontrolled inflammation can cause long-term joint damage.

“It’s a shame that these devices don’t seem to have any genuine benefit,” Richmond said. “They’re so simple and generally safe to use. But what these findings do tell us is that people who suffer with rheumatoid arthritis may be better off saving their money, or spending it on other complementary interventions, such as dietary fish oils for example, which have far better evidence for effectiveness.”

The research showed that both the standard magnetic wrist strap and the copper bracelet “provided no meaningful therapeutic effects beyond those of a placebo, which was not magnetic and did not contain copper,” a news release states.

Those who have tried these bracelets and believe it was helpful were probably wearing them during a flare-up, Richmond said. People may confuse when the symptoms naturally subside with a legitimate therapeutic effect.

“Pain varies greatly over time in conditions like rheumatoid arthritis, and the way we perceive pain can be altered significantly by the power of the mind,” Richmond said.

Magnet therapy is often privately used for the management of chronic pain, with estimated worldwide annual sales of devices exceeding one billion US dollars, the release states.

The practice of wearing copper bracelets to combat rheumatism has been popular since the 1970s. Previous research by Richmond and his colleagues, published in 2009, threw doubt on the effectiveness of such devices for osteoarthritis. The present study builds on and extends these findings, the release states.